Consulta: creatorFacets:"Chomerat, Nicolas"
Registros recuperados: 30
Data/hora: 07/06/2024 03:34:00

Genetic diversity of the harmful family Kareniaceae (Gymnodiniales, Dinophyceae) in France, with the description of Karlodinium gentienii sp. nov.: A new potentially toxic dinoflagellate
Provedor de dados: 5
Autores: Nezan, Elisabeth; Siano, Raffaele; Boulben, Sylviane; Six, Christophe; Bilien, Gwenael; Cheze, Karine; Duval, Audrey; Le Panse, Sophie; Quere, Julien; Chomerat, Nicolas.
The family Kareniaceae is mostly known in France for recurrent blooms of Karenia mikimotoi in the Atlantic, English Channel, and Mediterranean Sea and for the unusual green discoloration in the saltwater lagoon of Diana (Corsica) caused by Karlodinium corsicum in April 1994. In terms of diversity, this taxonomic group was long overlooked owing to the difficult identification of these small unarmored dinoflagellates. In this study, thanks to the molecular characterization performed on single cells from field samples and cultures, twelve taxonomic units were assigned to the known genera Karenia, Karlodinium and Takayama, whereas one could not be affiliated to any described genus. The molecular phylogeny inferred from the D1–D2 region of the LSU rDNA showed...
Tipo: Text
Palavras-chave: Genetic diversity; Haemolytic; Kareniaceae; Pigments; Single cell; Taxonomy.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00225/33611/32310.pdf

Morphology and molecular phylogeny of prorocentrum consutum sp. nov. (dinophyceae), a new benthic dinoflagellate from south Brittany (northwestern France)
Provedor de dados: 5
Autores: Chomerat, Nicolas; Sellos, Daniel Y.; Zentz, Frederic; Nezan, Elisabeth.
A new marine benthic Prorocentrum species from sandy habitats of South Brittany (northwestern France), P. consutum sp. nov., is described using LM and SEM and molecular phylogenetic analyses. Cells have a subcircular to broadly ovoid shape and are plainly flattened. They are 57-61 lm long and 52-55 lm wide. A central pyrenoid is present, and the kidney-shaped nucleus is positioned in the posterior region. In right valve view, the periflagellar area is deeply excavated, and the left valve forms a prominent apical ridge. The periflagellar area consists of nine platelets, and a small narrow collar is present around the flagellar pore. The ornamentation of this new species is very peculiar and is characterized by a ring of round areolae located at the...
Tipo: Text
Palavras-chave: Taxonomy; SSU rDNA; SEM; Prorocentrum; Nuclear DNA; Molecular phylogeny; LSU rDNA; Dinoflagellates.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/2010/publication-7449.pdf

Description and phylogenetic position of     Plagiolemma distortum     sp. nov., a new raphid diatom (Bacillariophyceae) from French coastal waters
Provedor de dados: 5
Autores: Nezan, Elisabeth; Bilien, Gwenael; Boulben, Sylviane; Mertens, Kenneth; Chomerat, Nicolas.
A new marine raphid diatom, Plagiolemma distortum Nézan, sp. nov. is described from plankton samples from the Atlantic Ocean, south Brittany (north-western France), where it was regularly observed, but never in high abundances. Cells have an unusual and complex shape under light microscopy (LM) depending on their position and orientation. The two valves are highly vaulted and narrow in width (transapical axis). Cells contain four complexly lobed plastids and a variable number of refractive granules without particular localization. In addition, capsules containing motile cells were observed. Ultrastructural details of the frustules were investigated using scanning electron microscopy (SEM). The girdle bands are simple. Each valve possesses a sigmoid raphe...
Tipo: Text
Palavras-chave: Capsules; Habitat; Molecular phylogeny; Plastids; Raphid diatom; Video.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00441/55235/56797.pdf

Taxonomic Re-Investigation and Geochemical Characterization of Reid’s (1974) Species of     Spiniferites     from Holotype and Topotype Material
Provedor de dados: 5
Autores: Gurdebeke, Pieter R.; Mertens, Kenneth; Bogus, Kara; Marret, Fabienne; Chomerat, Nicolas; Vrielinck, Henk; Louwye, Stephen.
The genus Spiniferites currently encompasses 142 dinoflagellate cyst species. Some Spiniferites species are difficult to identify because of an incomplete or doubtful description, and/or substandard iconography. This study re-describes and re-illustrates the Spiniferites holotypes first described by Reid in 1974 Reid PC. 1974. Gonyaulacacean dinoflagellate cysts from the British Isles. Nova Hedwigia. 25:579–637. [Google Scholar]. It also discusses topotype material from surface sediments recovered from British estuaries, and attempts to provide further constraints on the classification of species in this genus using the geochemical characterization of their cyst walls. Reid described four new Spiniferites species: Spiniferites belerius, Spiniferites...
Tipo: Text
Palavras-chave: Dinoflagellate cyst; Redescription; Taxonomy; Geochemistry; Cyst wall composition; FTIR; Dinosporin.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58306/60847.pdf

Pseudo-nitzschia australis on French Atlantic coast - an unusual toxic bloom
Provedor de dados: 5
Autores: Nezan, Elisabeth; Chomerat, Nicolas; Bilien, Gwenael; Boulben, Sylviane; Duval, Audrey; Ryckaert, Mireille.
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00008/11949/8657.pdf

Prorocentrum bimaculatum sp nov (Dinophyceae, prorocentrales), a new benthic dinoflagellate species from Kuwait (Arabian gulf)
Provedor de dados: 5
Autores: Chomerat, Nicolas; Saburova, Maria; Bilien, Gwenael; Al-yamani, Faiza.
A new benthic dinoflagellate species, Prorocentrum bimaculatum sp. nov., is studied from Kuwaits marine sediments, based on detailed morphological and molecular data. Cells are large, oblong oval in shape. They are 49.955.3 mu m long and 38.443.2 mu m wide. The ornamentation of this new species is peculiar, and characterized by smooth valves with large pores (0.320.50 mu m) scattered on their surface, except in two circular patches of similar to 15 mu m in diameter, devoid of ornamentation and located on both sides of the valve centers. The periflagellar area is widely triangular, located in a moderate excavation of the right valve, and comprises nine platelets. The intercalary band of P. bimaculatum is smooth. The molecular phylogenetic position of this...
Tipo: Text
Palavras-chave: Arabian Gulf; Benthic dinoflagellates; Kuwait; Molecular phylogeny; Morphology; Nuclear DNA; Prorocentrum; RDNA; SEM; Taxonomy.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00066/17756/15698.pdf

Ailadinium reticulatum gen. et sp. nov. (Dinophyceae), a New Thecate, Marine, Sand-Dwelling Dinoflagellate from the Northern Red Sea
Provedor de dados: 5
Autores: Saburova, Maria; Chomerat, Nicolas.
A new photosynthetic, sand-dwelling marine dinoflagellate, Ailadinium reticulatum gen. et sp. nov., is described from the Jordanian coast in the Gulf of Aqaba, northern Red Sea, based on detailed morphological and molecular data. A. reticulatum is a large (53–61 μm long and 38–48 μm wide), dorsoventrally compressed species, with the epitheca smaller than the hypotheca. The theca of this new species is thick and peculiarly ornamented with round to polygonal depressions forming a foveate-reticulate thecal surface structure. The Kofoidian thecal tabulation is APC (Po, cp), 4′, 2a, 6′′, 6c, 4s, 6′′′, 1p, 1′′′′ or alternatively it can be interpreted as APC, 4′, 2a, 6′′, 6c, 4s, 6′′′, 2′′′′. The plate pattern of A. reticulatum is noticeably different from...
Tipo: Text
Palavras-chave: Benthic dinoflagellates; Dinophyceae; Gulf of Aqaba; Jordan; LSU rDNA; Molecular phylogeny; Morphology; Red Sea; SSU rDNA; Taxonomy.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00226/33678/38183.pdf

Madanidinium loirii gen. et sp nov. (Dinophyceae), a new marine benthic dinoflagellate from Martinique Island, Eastern Caribbean
Provedor de dados: 5
Autores: Chomerat, Nicolas; Bilien, Gwenael.
A new benthic phototrophic dinoflagellate is described from sediments of a tropical marine cove at Martinique Island and its micromorphology is studied by means of light and electron microscopy. The cell contains small golden-brown chloroplasts and the oval nucleus is posterior. It is laterally compressed, almost circular in shape when viewed laterally. It consists of a small epitheca tilted toward the right lateral side and a larger hypotheca. In the left view, the cingulum is more anterior and the epitheca is reduced. The cingulum is displaced and left-handed. This organism is peculiar in having no apical pore and its thecal plate arrangement is 2 ' 1a 7 '' 5c 3s 5 ''' 1 ''''. The plates are smooth with small groups of pores scattered on their surface....
Tipo: Text
Palavras-chave: Caribbean; Benthic; Dinophyceae; SEM; Phylogeny; Morphology; Taxonomy; Martinique; RDNA.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00195/30622/29458.pdf

Record levels of Dinophysistoxin-2 in clams from Douarnenez Bay, France, after an unusual bloom of Dinophysis acuta
Provedor de dados: 5
Autores: Derrien, Amelie; Terre Terrillon, Aouregan; Duval, Audrey; Doner, Anne; Chomerat, Nicolas.
Tipo: Text
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00683/79481/82072.pdf

Adding new pieces to the Azadinium (Dinophyceae) diversity and biogeography puzzle: Non-toxigenic Azadinium zhuanum sp. nov. from China, toxigenic A. poporum from the Mediterranean, and a non-toxigenic A. dalianense from the French Atlantic
Provedor de dados: 5
Autores: Luo, Zhaohe; Krock, Bernd; Mertens, Kenneth; Nezan, Elisabeth; Chomerat, Nicolas; Bilien, Gwenael; Tillmann, Urban; Gu, Haifeng.
The marine planktonic dinophyceaen genus Azadinium is a primary source of azaspiracids, but due to their small size its diversity may be underestimated and information on its biogeography is still limited. A new Azadinium species, A. zhuanum was obtained from the East China Sea and Yellow Sea of China by incubating surface sediments. Five strains were established by isolating single germinated cells and their morphology was examined with light microscopy and scanning electron microscopy. Azadinium zhuanum was characterized by a plate pattern of Po, cp, X, 4′, 2a, 6′′, 6C, 5S, 6′′′, 2′′′′, by a distinct ventral pore at the junction of Po, the first and fourth apical plates, and a conspicuous antapical spine. Moreover, Azadinium poporum was obtained for the...
Tipo: Text
Palavras-chave: Azadinium; Azaspiracid; AZA-2; AZA-2 phosphate; Biogeography; China; French Atlantic; Mediterranean Sea.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00386/49765/51155.pdf

First record of resting cysts of the benthic dinoflagellate     Prorocentrum leve     in a natural reservoir in Gujan-Mestras, Gironde, France
Provedor de dados: 5
Autores: Mertens, Kenneth; Gu, Haifeng; Pospelova, Vera; Chomerat, Nicolas; Nezan, Elisabeth; Gurdebeke, Pieter; Bogus, Kara; Vrielinck, Henk; Rumebe, Myriam; Meteigner, Claire.
The resting cysts of the benthic dinoflagellate Prorocentrum leve from a natural reservoir in Gujan-Mestras (Gironde, France) were described in this study. The incubated urn-shaped cysts gave rise to cells of Prorocentrum leve. Morphological observations through light microscopy and scanning electron microscopy, particularly of the periflagellar platelets, combined with large subunit ribosomal DNA sequences obtained through single-cell analysis confirm their affinity to the species Prorocentrum leve. The cysts are characterized by a specific shape and the presence of an anterior plug. This is the first conclusive evidence for fossilizable resting stages within the Prorocentrales, one of the major orders within the Dinophyceae. Palynological treatments show...
Tipo: Text
Palavras-chave: Cellulosic; Micro-FTIR; Palynology; Prorocentrales; Resting stage.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00398/50971/51728.pdf

Dynamics of phytoplankton communities in eutrophying tropical shrimp ponds affected by vibriosis
Provedor de dados: 5
Autores: Lemonnier, Hugues; Lantoine, Francois; Courties, Claude; Guillebault, Delphine; Nezan, Elisabeth; Chomerat, Nicolas; Escoubeyrou, Karine; Galinie, Christian; Blockmans, Bernard; Laugier, Thierry.
Tropical shrimp aquaculture systems in New Caledonia regularly face major crises resulting from outbreaks of Vibrio infections. Ponds are highly dynamic and challenging environments and display a wide range of trophic conditions. In farms affected by vibriosis, phytoplankton biomass and composition are highly variable. These conditions may promote the development of harmful algae increasing shrimp susceptibility to bacterial infections. Phytoplankton compartment before and during mortality outbreaks was monitored at a shrimp farm that has been regularly and highly impacted by these diseases. Combining information from flow cytometry, microscopy, pigment and phylogenetic analysis, the presence of Picocyanobacteria, Prasinophyceae and Diatomophyceae were...
Tipo: Text
Palavras-chave: Tropical aquaculture pond; Litopenaeus stylirostris; Vibriosis; Eutrophication; Phytoplankton; Harmful algae.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00343/45411/44986.pdf

Taxonomic revision of     Spiniferites elongatus     (the resting stage of     Gonyaulax elongata     ) based on morphological and molecular analyses
Provedor de dados: 5
Autores: Van Nieuwenhove, Nicolas; Potvin, Eric; Heikkila, Maija; Pospelova, Vera; Mertens, Kenneth; Masure, Edwige; Kucharska, Malgorzata; Yang, Eun Jin; Chomerat, Nicolas; Zajaczkowski, Marek.
We restudied the morphological complex comprising the cyst-based species Spiniferites elongatus/Spiniferites frigidus/Rottnestia amphicavata. We reviewed existing studies, and acquired new morphometric measurements of recent cysts from across the Northern Hemisphere, scanning electron microscopy (SEM) observations of cysts from Barents Sea surface sediments, and genetic analyses of cysts from the Beaufort Sea. The measurements suggest that populations and morphospecies cannot be distinguished based on morphometric criteria. Furthermore, sequential sediment trap samples from Hudson Bay reveal that morphological variation can occur at the same location over a few weeks, arguing against a uniform morphological response to environmental parameters. The SEM...
Tipo: Text
Palavras-chave: Single-cell PCR; Spiniferites ellipsoideus; Spiniferites frigidus; Rottnestia amphicavata; Morphologic variability; Taxonomy.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00471/58305/60846.pdf

Seasonal succession of cyanoprokaryotes in a hypereutrophic oligo-mesohaline lagoon from the South of France
Provedor de dados: 5
Autores: Chomerat, Nicolas; Garnier, Robert; Bertrand, Céline; Cazaubon, Arlette.
The Bolmon lagoon (South of France) is an oligo-mesohaline coastal lagoon that has undergone intense eutrophication in the past decades, resulting from a strong concentration of human activities in its drainage basin. Consequently, it exhibits some characteristics typical of an advanced trophic state; namely, the disappearance of submerged vegetation, the permanently intense phytoplankton growth and the recurrence of cyanoprokaryote blooms. As cyanoprokaryote dominance in south-temperate saline lagoons is little reported, we carried out this study in order to understand the seasonal variations in the phytoplankton composition and biomass, and to analyse the influence of environmental parameters such as salinity, nutrients and climate on the seasonal...
Tipo: Text
Palavras-chave: Turbid state; Pseudanabaena limnetica; Planktothrix agardhii; Phytoplankton; Mediterranean area; Cyanoprokaryotes; Ecology; Lagoon; Brackish water.
Ano: 2007
URL: http://archimer.ifremer.fr/doc/2007/publication-2593.pdf

Morpho-molecular diversity and phylogeny of     Bysmatrum     (Dinophyceae) from the South China Sea and France
Provedor de dados: 5
Autores: Luo, Zhaohe; Lim, Zhen Fei; Mertens, Kenneth; Gurdebeke, Pieter; Bogus, Kara; Carbonell-moore, Maria Consuelo; Vrielinck, Henk; Leaw, Chui Pin; Lim, Po Teen; Chomerat, Nicolas; Li, Xintian; Gu, Haifeng.
The dinoflagellate genus Bysmatrum encompasses five epibenthic or tide-pool species and has been characterized by separated anterior intercalary plates. In the present study, we obtained six strains of Bysmatrum from the South China Sea and French Atlantic coast by isolating single cells/cysts from plankton and sediment samples. All strains were examined with light microscopy and scanning electron microscopy. Based on morphological observations, three strains were identified as Bysmatrum subsalsum, characterized by the elongated and rectangular first and a hexagonal second anterior intercalary plate. They differ from each other in the number of sulcal lists and the configuration of the first anterior intercalary plate. One strain was identified as...
Tipo: Text
Palavras-chave: Benthic dinoflagellate; Biogeography; Bysmatrum granulosum; Bysmatrum gregarium; Bysmatrum subsalsum; Eyespot; Molecular phylogeny.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00450/56188/57872.pdf

Fragilidium duplocampanaeforme sp nov (Dinophyceae): A new phagotrophic dinoflagellate from the French Atlantic coast
Provedor de dados: 5
Autores: Nezan, Elisabeth; Chomerat, Nicolas.
A new species of the genus Fragilidium, F. duplocampanaeforme sp. nov., is described from examinations by LM and SEM. This species has been recorded in summer on the French Atlantic coast, over a number of years. It was never abundant in the plankton and was very often associated with Fragilidium subglobosum, Pyrophacus horologium and also with toxigenic species of the genera Alexandrium and Dinophysis. Phagotrophy of F. duplocampanaeforme on Dinophysis prey is shown, and sexual reproduction is suggested by the observation of gamete-like small forms. The size and the peculiar shape of its cells do not correspond to any known taxon, but the plate arrangement fits the genus Fragilidium. The plate formula is Po, Pc, 4', 8 '', 10c, 6s?, 7"', 2 '''', lp. A...
Tipo: Text
Palavras-chave: Taxonomy; Phagotrophy; Fragilidium duplocampanaeforme sp nov.; Fragilidium; Dinophyceae; Atlantic ocean.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6233.pdf

Essai d'aptitude par comparaison Inter-Analystes pour l'évaluation des performances en identification et dénombrement du phytoplancton marin dans le cadre du REPHY. Résultats exercice 2016
Provedor de dados: 5
Autores: Neaud-masson, Nadine; Brun, Melanie; Chomerat, Nicolas.
La détermination des espèces phytoplanctoniques et l’estimation de leur abondance dans le cadre du Réseau d’observation et de surveillance du Phytoplancton et de l’Hydrologie, mis en œuvre par l’Ifremer (REPHY) s’appuie en 2016 sur 25 analystes, répartis dans 9 laboratoires sur 12 sites. Neuf d’entre eux ont été inscrits à titre individuel en 2016 pour participer à l'exercice d’inter-comparaison international (IPI)  organisé tous les ans par le Marine Institute Phytoplankton unit de Galway (Ireland). Les échantillons envoyés aux analystes concernés ont été utilisés pour évaluer aussi les compétences des analystes non-inscrits à l’IPI, mais réalisant également des analyses de phytoplancton dans ces mêmes laboratoires pour le REPHY. Au total, 23 analystes...
Tipo: Text
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00388/49923/50497.pdf

An emended description and phylogeny of the little-known     Prorocentrum sipadanense     Mohammad-Noor, Daugbjerg &amp; Moestrup (Prorocentrales, Dinophyceae) from the Indian Ocean, Oman
Provedor de dados: 5
Autores: Saburova, Maria; Chomerat, Nicolas.
A small Prorocentrum species was found during a pilot taxonomic survey of marine benthic dinoflagellates in the northwestern Arabian Sea, Oman. Based on the study of cells from natural samples and laboratory cultures using light and scanning electron microscopy, this taxon is attributed to the little-known Prorocentrum sipadanense, recorded so far only from East Malaysia. The description of this species has been emended to include details of internal cell structure, composition of its periflagellar area and intraspecific variability in size, shape and pore pattern. Round to oval or ovoid cells of P. sipadanese are surrounded by a prominent marginal ridge and are 17.9–23.9 µm long and 15.0–19.8 µm wide, with a foveate to reticulate thecal plate surface and...
Tipo: Text
Palavras-chave: Arabian Sea; Benthic dinoflagellates; Molecular phylogeny; Morphology; Oman; Prorocentrum sipadanense; Taxonomy.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00319/42990/42560.pdf

First report of goniodomin A production by the dinoflagellate Alexandrium pseudogonyaulax developing in southern Mediterranean (Bizerte Lagoon, Tunisia)
Provedor de dados: 5
Autores: Triki, Habiba Zmerli; Laabir, Mohamed; Moeller, Peter; Chomerat, Nicolas; Daly-yahia, Ons Kefi.
The dinoflagellate Alexandrium pseudogonyaulax is widely distributed around the world including the Mediterranean waters. The objectives of this study were to determine the morphology and phylogenic affiliation of A. pseudogonyaulax strain isolated from Bizerte Lagoon (Mediterranean waters, Tunisia) and investigate its toxicity. Molecular analyses confirmed the morphological identification of the isolated strain (APBZ12) as A. pseudogonyaulax. Moreover, it showed that it is 100% identical with strains of this species found in New Zealand, Japan, China and North Sea (Norway and Denmark) suggesting that this species is cosmopolitan. Until now, no toxin studies have been conducted on fully characterized (morphologically and molecularly) A. pseudogonyaulax....
Tipo: Text
Palavras-chave: Alexandrium pseudogonyaulax; Goniodomin A; Mediterranean sea; Morphology; Phylogeny.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00302/41356/40548.pdf

Ovatoxin-a and Palytoxin Accumulation in Seafood in Relation to Ostreopsis cf. ovata Blooms on the French Mediterranean Coast
Provedor de dados: 5
Autores: Amzil, Zouher; Sibat, Manoella; Chomerat, Nicolas; Grossel, Hubert; Marco-miralles, Francoise; Lemee, Rodolphe; Nezan, Elisabeth; Sechet, Veronique.
Dinoflagellates of the genus Ostreopsis are known to cause (often fatal) food poisoning in tropical coastal areas following the accumulation of palytoxin (PLTX) and/or its analogues (PLTX group) in crabs, sea urchins or fish. Ostreopsis spp. occurrence is presently increasing in the northern to north western Mediterranean Sea (Italy, Spain, Greece and France), probably in response to climate change. In France, Ostreopsis. cf. ovata has been associated with toxic events during summer 2006, at Morgiret, off the coast of Marseille, and a specific monitoring has been designed and implemented since 2007. Results from 2008 and 2009 showed that there is a real danger of human poisoning, as these demonstrated bioaccumulation of the PLTX group (PLTX and ovatoxin-a)...
Tipo: Text
Palavras-chave: Ostreopsis cf. ovata; Palytoxin; Ovatoxin-a; LC-MS/MS; Seafood.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00071/18230/15799.pdf

Complex Toxin Profile of French Mediterranean Ostreopsis cf. ovata Strains, Seafood Accumulation and Ovatoxins Prepurification
Provedor de dados: 5
Autores: Brissard, Charline; Herrenknecht, Christine; Sechet, Veronique; Herve, Fabienne; Pisapia, Francesco; Harcouet, Jocelyn; Lemee, Rodolphe; Chomerat, Nicolas; Hess, Philipp; Amzil, Zouher.
Ostreopsis cf. ovata produces palytoxin analogues including ovatoxins (OVTXs) and a putative palytoxin (p-PLTX), which can accumulate in marine organisms and may possibly lead to food intoxication. However, purified ovatoxins are not widely available and their toxicities are still unknown. The aim of this study was to improve understanding of the ecophysiology of Ostreopsis cf. ovata and its toxin production as well as to optimize the purification process for ovatoxin. During Ostreopsis blooms in 2011 and 2012 in Villefranche-sur-Mer (France, NW Mediterranean Sea), microalgae epiphytic cells and marine organisms were collected and analyzed both by LC-MS/MS and hemolysis assay. Results obtained with these two methods were comparable, suggesting ovatoxins...
Tipo: Text
Palavras-chave: Ostreopsis cf. ovata; Palytoxin &amp; ovatoxins; Culture; Seafood contamination; LC-MS/MS; Hemolysis assay; Mediterranean Sea.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00199/31025/29428.pdf

Essai d'aptitude par comparaison Inter-analystes pour l'évaluation des performances en identification et dénombrement du phytoplancton marin. Rapport d'évaluation des compétences des analystes du phytoplancton dans le cadre du réseau d'observation et de surveillance du phytoplancton et de l'hydrologie (REPHY) mis en oeuvre par l'Ifremer
Provedor de dados: 5
Autores: Neaud-masson, Nadine; Brun, Melanie; Chomerat, Nicolas.
The determination of phytoplankton species and the estimation of their abundance in the context of the Phytoplankton and Hydrology Monitoring and Surveillance Network, implemented by Ifremer (REPHY), is based in 2017 on 21 analysts spread over 12 sites. Proficiency testing by inter-laboratory or inter-analyst comparison is used to evaluate the performance of laboratories or analysts on specific skills. An International Phytoplankton Inter-comparison (IPI) is organized annually by the Marine Institute Phytoplankton unit of Galway (Ireland), to evaluate marine phytoplankton identification and enumeration performance. The IPI is implementing its inter-comparison exercises through the Marine Institute Ireland in cooperation with the Intergovernmental...
Tipo: Text
Palavras-chave: Phytoplancton; Comparaison Inter-Laboratoire; CIL; Comparaison Inter-Analyste; CIA; Essai d’aptitude; Phytoplankton; Inter-Laboratory Comparison; CIL; Inter-Analyst Comparison; CIA; Aptitude Test; International Phytoplankton Inter-comparison; IPI.
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00436/54797/56255.pdf

Cyanobactéries dans le Lac d’Hossegor en 2013
Provedor de dados: 5
Autores: Rumebe, Myriam; Auby, Isabelle; Chomerat, Nicolas; Amzil, Zouher; Costa, Magali; Arrue, François.
Cette note concerne une efflorescence de cyanobactéries du genre Planktothrix dans le Lac marin d'Hossegor, en janvier 2013. La provenance de ces microalgues a été identifiée et leur innocuité démontrée grâce aux résultats d'analyses des phycotoxines.
Tipo: Text
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00167/27834/26040.pdf

Evolutionary processes and cellular functions underlying divergence in Alexandrium minutum
Provedor de dados: 5
Autores: Le Gac, Mickael; Metegnier, Gabriel; Chomerat, Nicolas; Malestroit, Pascale; Quere, Julien; Bouchez, Olivier; Siano, Raffaele; Destombe, Christophe; Guillou, Laure; Chapelle, Annie.
Understanding divergence in the highly dispersive and seemingly homogeneous pelagic environment for organisms living as free drifters in the water column remains a challenge. Here, we analyzed the transcriptome wide mRNA sequences, as well as the morphology of 18 strains of Alexandrium minutum, a dinoflagellate responsible for Harmful Algal Blooms worldwide, to investigate the functional bases of a divergence event. Analysis of the joint site frequency spectrum (JSFS) pointed toward an ancestral divergence in complete isolations followed by a secondary contact resulting in gene flow between the two diverging groups, but heterogeneous across sites. The sites displaying fixed SNPs were associated with a highly restricted gene flow and a strong...
Tipo: Text
Palavras-chave: Dinoflagellates; Harmful algal blooms; Populations Genomics; Pseudocryptic species; Speciation.
Ano: 2016
URL: http://archimer.ifremer.fr/doc/00347/45857/45529.pdf

Toxin and Growth Responses of the Neurotoxic Dinoflagellate Vulcanodinium rugosum to Varying Temperature and Salinity
Provedor de dados: 5
Autores: Abadie, Eric; Muguet, Alexia; Berteaux, Tom; Chomerat, Nicolas; Hess, Philipp; Roque D'Orbcastel, Emmanuelle; Masseret, Estelle; Laabir, Mohamed.
Vulcanodinium rugosum, a recently described species, produces pinnatoxins. The IFR-VRU-01 strain, isolated from a French Mediterranean lagoon in 2010 and identified as the causative dinoflagellate contaminating mussels in the Ingril Lagoon (French Mediterranean) with pinnatoxin-G, was grown in an enriched natural seawater medium. We tested the effect of temperature and salinity on growth, pinnatoxin-G production and chlorophyll a levels of this dinoflagellate. These factors were tested in combinations of five temperatures (15, 20, 25, 30 and 35 °C) and five salinities (20, 25, 30, 35 and 40) at an irradiance of 100 µmol photon m−2 s−1. V. rugosum can grow at temperatures and salinities ranging from 20 °C to 30 °C and 20 to 40, respectively. The optimal...
Tipo: Text
Palavras-chave: Vulcanodinium rugosum; Mediterranean Ingril Lagoon; Toxin production; Growth conditions; Temperature; Salinity.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00333/44429/44095.pdf

Cabra reticulata sp. nov. (Dinophyceae), a new sand-dwelling dinoflagellate from the Atlantic Ocean
Provedor de dados: 5
Autores: Chomerat, Nicolas; Nezan, Elisabeth.
A new sand-dwelling dinoflagellate species, Cabra reticulata sp. nov., is described from sandy habitats in the south of Brittany (northwestern France). This new species possesses the characteristics of the 'unusual' genus, Cabra Murray et Patterson. The thecal plate formula is Po Pt 3' 1a 4'' 'x' 3c ?s 5''' 1'''' (or alternatively interpreted as Po Pt 4' 0a 4'' 'x' 3c ?s 5''' 1''''). Because of the strong lateral compression, cells of C. reticulata are frequently seen laterally and have a polygonal shape, with three prominent antapical pointed flanges and a dorsal spine in the anterior part of the hypotheca. The cingulum is ascending and incomplete. The thecal surface is ornamented with strong reticulations forming polygonal areolae, which differs from C....
Tipo: Text
Palavras-chave: Taxonomy; Sand dwelling; Roscoffia; Protists; Podolampaceae; Marine; Dinophyceae; Benthic.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6804.pdf

Micro-algues des claires ostréicoles de Charente Maritime : focus sur les producteurs potentiels de toxines DSP, PSP et ASP et toxines émergentes (palytoxines, pinnatoxine...)
Provedor de dados: 5
Autores: Mertens, Kenneth; Chomerat, Nicolas; Nezan, Elisabeth; Bruneau, Audrey; Le Bec, Claude.
Les inspections vétérinaires de la Commission Européenne ayant signifié à la France son constat d'une absence de réserau de surveillance sur les claires ostréicoles, la DGAL a mandaté l'Ifremer afin de réaliser un premier diagnostic sur le phytoplancton. Cette commande de la DGAL place l'Ifremer LERBO comme prestataire de service et spécialiste des micro-algues. Les claires ostréicoles étant hors du domaine public maritime, une concertation avec le Comité Régional de la Conchyliculture de Poitou-Charentes, la DGAL et la DDTM 17 en juin 2018 a permis de proposer six claires, réparties entre l'île de Ré et l'île d'Oléron et pouvant être échantillonnées. L'objectif est de faire un état des lieux de la présence ou de l'absence de cellules de phytoplancton...
Tipo: Text
Palavras-chave: Charentes; Claire; Phytoplancton; Micro-algue; Toxine.
Ano: 2019
URL: https://archimer.ifremer.fr/doc/00486/59731/62828.pdf

Micro-algues toxiques et nuisibles de l’océan mondial. COI Manuels et Guides, 68
Provedor de dados: 5
Autores: Lassus, Patrick; Chomerat, Nicolas; Hess, Philipp; Nezan, Elisabeth.
This book updates available international databases on toxic and harmful species of phytoplankton and micro-phytobenthos. It lists regional occurrences at world-wide scale: localities, cell densities, toxicity levels in contaminated animals, human and animal poisoning, isolation of identified active molecules and toxins, documentary sources. Finally, this book addresses the geographic distributions of phycotoxin-producers from recent data. The objective is to analyze the evolution of toxic and harmful episodes over the past 30 years to identify trends, and to introduce a discussion on the reality of a time-dependent increase in the number of known species and toxins.
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00379/49054/49508.pdf

Toxicity and Growth Assessments of Three Thermophilic Benthic Dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima and Coolia monotis) Developing in the Southern Mediterranean Basin
Provedor de dados: 5
Autores: Ben-gharbia, Hela; Yahia, Ons Kefi-daly; Amzil, Zouher; Chomerat, Nicolas; Abadie, Eric; Masseret, Estelle; Sibat, Manoella; Triki, Habiba Zmerli; Nouri, Habiba; Laabir, Mohamed.
armful benthic dinoflagellates, usually developing in tropical areas, are expanding to temperate ecosystems facing water warming. Reports on harmful benthic species are particularly scarce in the Southern Mediterranean Sea. For the first time, three thermophilic benthic dinoflagellates (Ostreopsis cf. ovata, Prorocentrum lima and Coolia monotis) were isolated from Bizerte Bay (Tunisia, Mediterranean) and monoclonal cultures established. The ribotyping confirmed the morphological identification of the three species. Maximum growth rates were 0.59 ± 0.08 d−1 for O. cf. ovata, 0.35 ± 0.01 d−1 for C. monotis and 0.33 ± 0.04 d−1 for P. lima. Toxin analyses revealed the presence of ovatoxin-a and ovatoxin-b in O. cf. ovata cells. Okadaic acid and...
Tipo: Text
Palavras-chave: Ostreopsis cf. ovata; Prorocentrum lima; Coolia monotis; Southern Mediterranean Sea; Growth; Toxicity.
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00355/46585/46393.pdf

Three Dinophyceae from Clipperton Island lagoon (eastern Pacific Ocean), including a description of Peridiniopsis cristata var. tubulifera var. nov.
Provedor de dados: 5
Autores: Coute, Alain; Perrette, Catherine; Chomerat, Nicolas.
Clipperton Island is a small French coral atoll in the eastern Pacific Ocean, which has been rarely investigated because of its remote location and difficult access. There is little scientific information on this ecosystem and only a few microalgae have been reported from the lagoon. To date, only one dinoflagellate taxon, Peridiniopsis cristata, is known to inhabit the lagoon. During an expedition in 2005 to study the lagoon and the surrounding oceanic waters of Clipperton Island, a further investigation of the lagoon phytoplankton was undertaken. In addition to P. cristata, which was still abundant in the upper water layer, two other thecate dinoflagellates were recorded. One dinoflagellate was identified as Durinskia baltica, while the other had the...
Tipo: Text
Palavras-chave: Dinoflagellates; Lagoon; Morphology; Phytoplankton; Taxonomy.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00070/18086/15633.pdf